


Derailed

by AkinoAme



Category: Ben 10 Series, Kamen Rider Den-O
Genre: Action/Adventure, Ambiguous Relationships, F/M, Friendship, Humor, Time Travel, Troll ships, Ultimate Alien, break-up
Language: English
Status: In-Progress
Published: 2014-05-29
Updated: 2014-08-08
Packaged: 2018-01-27 01:17:17
Rating: Teen And Up Audiences
Warnings: No Archive Warnings Apply
Chapters: 2
Words: 8,884
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/1709690
Author URL: https://archiveofourown.org/users/AkinoAme/pseuds/AkinoAme
Summary: <blockquote class="userstuff">
              <p>After a careless wish, Ben finds himself in a world where he never existed. Now, if he stands any chance of setting things right, he has to join with four unusual creatures for a time-trippin' ride that will make him wonder what he really should wish for.</p>
<p>Meanwhile, Julie meets a young man who has his own plan to save the flow of time...</p>
            </blockquote>





	1. What Did Butterflies Ever Do To You?

**Author's Note:**

  * Inspired by [Almost Here](https://archiveofourown.org/external_works/52460) by Eternal-Night-Ride. 



            The sun was just dipping below the horizon and the earliest stars were shining as Ben ran for the school’s tennis court, desperately hoping he’d make it. But once he reached the bleachers, he knew he was too late. The stands were mostly empty, except for a few friends and family members congratulating the players. Julie was standing with her parents, her racket zipped up in its case. The moment her father caught sight of Ben, his face went grim, and Ben couldn’t help but wince. Julie turned around to see him, and disappointment was written all over her face.

            “You’re late,” she said flatly as he walked over to her.

            “I know,” he answered. “And I’m sorry. But there was this alien attacking Chicago—a Rath, and you know how hard he is to handle.” The look Julie was giving him was dangerously close to a glare, and his face fell. “It was an emergency.”

            “That’s what you said last time,” she pointed out, looking down.

            Neither one could look at each other, and Julie’s parents decided to give them some time alone. For a long time, Ben didn’t know what to say, how to apologize. How exactly could he explain that he was trying his hardest, that he’d wanted to be there but he couldn’t exactly tell the Plumbers no? That when he tried to speed up the fight by going Ultimate, Gwen told him he was overdoing it and he’d only put more people in danger?

            “I’m sorry,” he tried again.

            “I barely see you anymore,” she said. “You never have time for me.”

            “That’s not true,” Ben protested. “I…”

            “There’s always something,” Julie insisted. “You come over to my house, and an alien attacks. We try to have lunch together, but the press chases you off. And that’s when we actually plan something. Otherwise, you’re running around all over the galaxy.”

            “I can’t help it,” Ben said. “I can’t just drop everything. They _need_ me—it’s my responsibility.”

            Was that a tear that had fallen on the ground in front of Julie, or was it his imagination? Her voice sounded steady as she said, “I know. But you have a responsibility to _me_ too.”

            “I…” Ben tried, but he couldn’t figure out the right thing to say.

            “Considering how little time you have for me lately, we might as well be broken up.”

            Ben looked at her in shock, feeling the world shatter. She’d promised she’d always be there for him. That no matter what troubles his fame brought him, she still loved him. This couldn’t be happening. Not after everything they went through—they’d been there for each other all this time, through the absolute worst, and she was breaking up with him?

            “Ben!”

            Gwen’s voice cut through his shock, and he turned around to see her and Kevin running toward him.

            “You’re not answering your phone or the Ultimatrix,” Gwen scolded.

            “The Plumbers just called,” Kevin explained. “Havoc escaped. He’s in Tokyo right now, so I hope you like sushi.”

            Ben didn’t know what to do. The team needed him right now, but Julie…

            “Go,” she said softly behind him. He turned around to look at her and saw that her eyes were closed, without a trace of tears.

            Pain turned into anger, and he swept up the pieces of his broken heart as he coldly answered, “Fine. If that’s what you want, I’m gone.”

            Before anyone could stop him, he turned and ran away, making a beeline for the Rustbucket, for Tokyo, for anywhere that was away from here. It would be afternoon in Japan, so the stars in the sky right now wouldn’t be mocking him.

            He didn’t notice one of the stars drop from the sky and enter him. He just assumed it was the feeling of the knife in his back twisting. Nor did he hear the voice whispering to him or see the head rising out of the sand. He just ran through it, kicking up a sandstorm as he tried to run away from it all.

            And somewhere in time, a demonic-looking creature in red stopped mid-argument and looked out the window of a speeding train.

            “I smell an Imagin.”

            “Eh?” asked one of his human companions. “Are you sure?”

            “Of course I’m sure! I’d know that smell anywhere! Let’s go!”

 

Derailed  
Chapter One: “What Did Butterflies Ever Do To You?”

 

            One pair of hands caught the clawed fist heading directly to his stomach while the other punched Havoc in the jaw. Havoc reeled but soon recovered, roaring at Four-Arms. He brought in both fists, claws out, toward Four-Arms’s head, but a pink energy shield formed just in time to block it.

            “Focus, Ben,” Gwen warned. “You can’t afford to lose your temper out here!”

            “I’m fine,” he growled between clenched teeth. He glared at her, and she decided against arguing with him, opting to rejoin the battle.

            Kevin had absorbed the pavement and had his hands morphed into sledgehammers, swinging wildly at Havoc. Normally, an all-out melee battle would be dangerous, but Japanese civilians were good about keeping far away from attacks. It made Ben feel better about going all-out himself, and he reached for the Ultimatrix.

            _“Tell me your wish.”_

            Ben stopped suddenly, glancing around. The voice almost sounded familiar, but it wasn't Gwen or Kevin, and nobody else was around either.

            He shook his head, muttering, “Great. Now I’m hearing things. This is perfect.”

            He set his hand on the Ultimatrix and changed forms, shouting, “Humongousaur!” a second later. Tough plates formed along his back and head as extra protection as he charged Havoc, plowing through sand along the way. Immediately, Gwen and Kevin got out of the way as Humongousaur rammed into Havoc, sending him flying across the street and into the front door of a café.

            “Ben!” Gwen shouted. “We’re not here to destroy the city!”

            “You got a better way to take him down?” Humongousaur challenged. “Remember what he did in Chicago?”

            “Hey, stop taking this out on us,” Kevin argued, ignoring the look of horror and then the growl of anger Humongousaur gave him in response. “Let’s take this guy in already.”

            “Fine by me,” Humongousaur growled, growing to his maximum height. He picked up Havoc and held him over his head for a moment before slamming him toward the ground.

            _“I will grant any wish.”_

            The voice came again, but disappeared with a burst of sand from Humongousaur’s attack. The ground fractured from the impact, with sand slipping down the cracks in the earth. As Havoc lay unconscious on the ground, for all intents and purposes harmless, Ben transformed back to human.

            “There,” he said, giving his friends a hard look. “He’s down.”

            “You really need to tone it down with the attitude,” Gwen replied, crossing her arms.

            “Hey!” Ben shouted, his temper flaring. “You try going through what I did today! Then you can tell me—”

            While he was in the middle of his rant, Havoc sprang to his feet with a roar of fury. Ben had no time to react as Havoc struck him across the face, dropping him to the ground. He was faintly aware of Gwen and Kevin calling his name, but his consciousness was slipping fast.

            He could make out one more voice, however—the unknown whisper in his mind:

            _“Just pay me one thing.”_

 

~~~

 

            There was sand in his eyes. Ben squeezed his eyes tighter, but the grit in his eyes wouldn’t relent.

            “Oh? I think he’s waking up.”

            The voice wasn’t familiar, so out of instinct, he opened his eyes and tried to sit up, but sharp pain shot through the side of his head. Gentle hands helped him into a sitting position as he clamped a hand over one of his temples.

            “Thank you, Ms. Nogami,” Gwen said as she came over to Ben’s side. The woman that had helped Ben smiled at them and got up, taking a bowl of water and a cloth away with her.

            Ben took a moment to look around, realizing he was in some kind of café. The smell of coffee came from the counter, where the woman accepted a cup from Kevin and took it to the sink. All around the café were books on stars and astronomy memorabilia—the most obvious an antique telescope on display.

            “What…” Ben started.

            “This is Ms. Nogami’s coffee shop,” Gwen explained. “She told us to get you inside when you got hit, and she’s been keeping an eye on you since. It’s especially nice, considering we smashed her front door.”

            “It’s no problem,” Ms. Nogami insisted. “These things happen.”

            “Thanks,” Ben said to her, and she smiled in return. “What happened to Havoc?”

            “Backup finally showed,” Kevin said, walking over. “Weirdest bunch of Plumbers I ever saw, though.”

            “I don’t know if they _were_ Plumbers,” Gwen pointed out.

            Kevin shrugged. “They had a badge and managed to call in a transport ship. Maybe they were the SWAT team?”

            Ben stood up, feeling a wave of dizziness the moment he started to get to his feet. He swayed dangerously, but Gwen and Kevin held him steady.

            “You need to take it easy,” Gwen warned. “Havoc hit you pretty hard. We couldn’t get you to wake up.”

            Bitterness and heartbreak surged within him, and Ben couldn’t help but mutter, “Maybe I shouldn’t have.”

           Gwen sighed, and the look Kevin gave him was so unusually sympathetic that Ben couldn’t take it anymore. Offering a last thank you to Ms. Nogami, he slowly walked out the broken door.

            “Ben, wait up!” Gwen called as they followed him out. “We need to talk.”

            “No, we don’t,” Ben said flatly.

            Kevin grabbed his shoulder and forcefully turned him around. Ben flinched in pain, but he met Kevin’s stare evenly as his friend insisted, “ _Now_ , Ben.”

            “We heard what Julie said,” Gwen admitted.

            Ben pulled himself away from Kevin and started to walk off. “Then you know everything you have to.”

            “Listen!” Gwen cried. “We’re sorry about what happened, but I don’t think she was saying what you heard. She’s just frustrated…”

            Ben came to a stop and turned back to glare at her. Grains of sand started to drop off of his body and onto the ground, but it was such a small amount that nobody noticed. “What, that I’m only there for her whenever she needs me? I did everything I could to be there for her games and everything else. I can’t _help_ it if an alien’s attacking Chicago or Tokyo at the same time she’s in Bellwood. She _knows_ that! And even when I am there, I can’t show my face without having a camera and microphone shoved at me. I’m _trying_.”

            “We know you are,” Gwen insisted.

            “And you know what’s worse?” he added. “She said she’d be there for me. When all of this went down and my secret got out, she said she was still there for me. Now all of a sudden, when it’s inconvenient for _her_ , she dumps me?”

            “Nobody’s saying your life’s exactly roses,” Kevin said. “But right now, you need to cool down and stop worrying about her for a minute…”

            “Stop worrying?” Ben shouted. “You try having the one person who promised she’d always be there just _drop_ you out of nowhere! And why? Because your life is completely out of your control. I never wanted any of this—not the cameras, not the stalkers, not the pundits turning me into Public Menace Number One!”

            The sand was pouring off of him in greater amounts now, collecting in a heap on the ground. Ben was too angry to notice, but Gwen tugged on Kevin’s arm and pointed.

            “You gotta calm down,” Kevin insisted.

            “How can I calm down?” Ben demanded. “I just want everyone to forget I even existed. You know what? Maybe I just wish I never existed at all. Maybe _that_ would fix things.”

            The sand stopped flowing, leaving a pile on the ground around Ben. The pile of sand then coalesced into a head and upper body, with a pair of legs made of sand hovering in the air over it. The legs lowered to the ground and the head rose until a whole form appeared and solidified.

            It was a girl, or as close to the concept as possible. Her short hair was made of green vines, rising into a bun like a pumpkin's stem. Her skin was pale orange, much paler than the short, pumpkin-shaped dress she wore. Vines ran down her arms and legs, and on her feet were green glass slippers. But it was her face that startled everybody.

            "She looks just like Julie," Gwen gasped.

            The Cinderella-Julie creature turned to Ben and held out her hand, as if asking him to dance.

            "Your wish shall be granted," she said in Julie's voice.

            The next thing anyone knew, a bright green line formed down Ben’s body, splitting him in half. The two halves opened, revealing a swirling grey vortex, and the creature flew within.

            “Ben!”

            Gwen and Kevin shouted together as they ran toward Ben, whose body sealed itself up once the creature had gone. He staggered backwards and fell, an expression of numb terror on his face. As they knelt next to him, Gwen wasted no time trying to sense the creature’s presence.

            “Find anything?” Kevin asked anxiously.

            “No,” Gwen said, her eyes glowing. “I can’t sense it anywhere inside him! Whatever it’s doing, it’s keeping too far out of my reach.”

            All at once, Ben’s life seemed to flash before his eyes. Time went backward from that point, and in his mind, he heard the chimes of the midnight bell: one, two, three...

            “Something’s wrong,” he murmured in a daze.

            “Yeah, no kidding!” Kevin answered.

            Ben shook his head. “She’s in my memories. I don’t know what she’s doing, but I can hear the bells.” Four, five, six... "When they reach twelve, something's going to happen. They'll be gone."

            Kevin looked to Gwen cautiously. “You think it’s trying to brainwash him?”

            “I don’t know,” she admitted.

            “No,” Ben insisted. Seven, eight, nine... “I’m not forgetting, but it’s…”

            “Out of the way!” shouted an unfamiliar voice as someone pushed his way over. Ben had only a glimpse of spiked hair and startlingly red eyes before a train ticket obscured his view. “Come on, what’s the date?” Ten, eleven...

            Twelve.

            All of a sudden, a bright white light washed through the landscape, making everything fade. Ben gasped in shock and got to his feet, and the other kid turned and swore as the whiteness spread, taking out Gwen and Kevin before anyone could stop it.

            “Got to get back to…” the kid started.

            There was a red flash from the kid’s body, like something was leaving it, but soon, the nothingness caught up with him too. He disappeared, leaving Ben alone in the blankness, staring up as faint, rainbow colors slowly spread across the sky.

            And suddenly, it was a sky again—iridescent, yes, but still recognizably a sky. The blankness was gone, and Ben was standing in an unfamiliar desert under an unknown sky.

            “What?” he asked. “Where…”

            “Ben Tennyson.”

            Ben turned around to see a stern-looking Asian man with a cane standing in front of a bullet train. Though Ben looked around, he didn’t see any sign of civilization, which made the train appear out-of-place. Even stranger, there didn’t appear to be any tracks ahead of it, and only a few behind.

            “What’s going on?” he asked.

            But the man continued to look serious, only answering, “DenLiner awaits.”

            The man turned and walked inside the train, and having no other choice, Ben followed him. The man led him past the junction between cars and into a dining car, where a red, demonic-looking creature sat moodily at a table, shooting him an odd glare. Ben wondered briefly if he’d done anything to annoy this alien, but before he could ask, a perky young woman with a shock of hot pink in her hair jumped into his line of sight.

            “Hi!” she greeted. “Welcome to DenLiner. Coffee?”

            Without even waiting for an answer, she thrust a cup at him, pointing him to a table. It was just to the side of where the red alien was, giving him a perfect vantage point to shoot Ben another death glare. Trying to ignore him, Ben sat down and started to take a sip of his coffee. He stopped quickly when he realized it was covered in what looked distinctly like cake icing. He liked sugar as much as the next person, but this seemed to be pushing it.

            “What’s wrong?” the alien asked critically. “Coffee not good enough for you?”

            Ben set down the cup, trying for his most neutral tone. “I’m not much of a coffee drinker.”

            “Momotaros-kun, that’s enough,” the man said, walking over. “Naomi-kun, please close down the dining car.”

            “Okay!” the server answered cheerfully.

            As Naomi began calling the announcement into a phone, the man fixed Ben with a critical look. Between the man analyzing him and the creature glaring at him, he was really beginning to feel uncomfortable. Unable to take it any longer, he burst out, “What’s going on? Where are my friends? And what is this place?”

            To his surprise, the man smiled in amusement. “Paradox-hakase said you would be full of questions.”

            “Wait, Paradox?” Ben asked, ignoring the unfamiliar word. “You know Paradox?”

            The man nodded. “He also wanders the path of time, though through a different method than we use.”

            He paused, as if for dramatic effect, and Ben waited for him to continue. When he didn’t, he asked, “And you use?”

            “Tch,” the creature, Momotaros, replied. “And I thought Ryotaro took a while to catch on. DenLiner is a time train—we’re traveling through time right now!”

            Ben stared at Momotaros in disbelief. “You’re kidding.”

            “No,” the man answered. “DenLiner, along with other time-trains, travels the rails of time. Only those with a ticket or a pass are allowed to travel through time. Which reminds me.” He reached into the breast pocket of his coat and removed a small, black metal pass. “Paradox-hakase asked me to give this to you.”

            “A Rider Pass?” Momotaros asked angrily, jumping to his feet. “Owner, how can you give it to this kid? What about Ryotaro?”

            “You’re getting ahead of yourself, Momotaros-kun,” Owner scolded. “There is still much that Ben-kun needs to know.”

            Owner gave Momotaros a heavy look until he calmed and sat back down. Ben silently watched Momotaros’s explosion, but he couldn’t help but feel a bit of sympathy. Whatever had happened to his friend, Ben couldn’t help but feel the same worry about his own friends.

            “What happened to my friends?”

            Without betraying emotion, Owner asked, “Has Paradox-hakase explained to you what a singular point is?” When Ben shook his head, he continued, “A singular point is a person who is unaffected by changes in the timeline. They can exist outside of time, and their memories remain constant, no matter what happens to their pasts. Like Momotaros-kun’s friend, Ryotaro-kun, you too are a singular point.”

            Ben slowly nodded, remembering how Paradox had explained to the younger version of him at the Forge of Creation that his memories wouldn’t be entirely gone. “Okay, so what’s so important about a singular point?”

            “Feh,” Momotaros commented. “Only a singular point can become Den-O.”

            “Kamen Rider Den-O is the protector of the timestream, a warrior for DenLiner,” Owner added. “There is only one person known who can become a Kamen Rider without being a singular point, but he is a special case.”

            “So because I remember what originally happens in the timeline, I can help keep it all straight?” Ben guessed, eliciting a nod from Owner. “But what’s threatening it?”

            Owner’s answer was simple and mysterious: “The Imagin.”

            Ben had the feeling that Owner was going for a deep, enigmatic atmosphere. Unfortunately, he didn’t have much patience for it. “Ima what?”

            “Imagin,” Momotaros answered. “Like me—we possess people, grant wishes, and destroy the timeline.”

            Ben gave Momotaros a look of shock before Owner explained, “Momotaros-kun and a few others like him chose to preserve the future rather than destroy it. The Imagin are formless beings until they possess someone with a subconscious wish, taking the form of something from their imagination.”

            “Imagine,” Ben murmured in realization. “So that thing that came out of me? Was it an Imagin?”

            “Correct,” Owner replied. “Normally, singular points are resistant to their temptations, but this one was particularly determined, and they can be clever. One careless comment was enough to be taken as a wish.”

            “But I didn’t wish…” Ben started before remembering just what he’d said, and he went silent in shock.

            “You mistakenly wished not to exist, for no one to remember you,” Owner pointed out. “Imagin have the power to connect to a person’s most precious memory and use it to travel back in time to destroy the timeline. That Imagin flew into your memories and erased you from the timeline. But because of all you had done when you were within time, the timeline you affected is now gone.”

            “Lucky you,” Momotaros said derisively to a shell-shocked Ben. “You don’t exist, but you still do.”

            Ben held his head in his hands, stunned. This was the biggest mistake he’d ever made. He’d always known that one little slipup could end in someone dying, and he’d had some pretty staggering odds before, but it had never been like this. He hadn't been careful, and now he'd stepped on a butterfly—a mistake big enough to destroy the timeline itself.

            He knew he couldn’t afford to feel sorry for himself right now. He looked back up at Owner with a steely expression, one that even took Momotaros aback. “How do I fix it?”

            Owner smiled with pride, as if Ben had passed some kind of test. “Your memories hold the key. They provide a tenuous link to the timeline.”

            “How?” Ben asked. “It doesn’t exist anymore, right?”

            “Memory is a powerful thing,” Owner insisted. “As long as something is remembered, it is never truly destroyed. Which is why the Imagin will come after you again.”

            “To finish me off?” Ben guessed.

            “No, for payment,” Momotaros answered. “Now that she’s fulfilled the contract, your strongest memory’s the last thing she needs to fly to.”

            “My strongest memory?” Ben repeated.

            Owner flicked his hand, producing a ticket between his fingers. He flipped it around and set it against Ben’s head. Seconds later, a date appeared, in June 2007. He flipped it back around to show Ben and asked, “Do you remember this date?”

            “That was the last day of school six years ago,” Ben said, taking the ticket in surprise. He held it gingerly, as if anything else might destroy his fragile link to the past. “It’s the day Grandpa took me and Gwen on the road trip for the summer, the night I found the Omnitrix.” He looked up at Owner. “Is this what the Imagin wants?”

            “So it would appear,” Owner answered.

            “I’ve got to stop him,” he decided, standing up. “But how?”

            “Momotaros-kun?” Owner asked.

            The Imagin sighed. “Take him to DenBird?”

            Owner nodded. “Also, you will have to help Ben-kun just as you did Ryotaro-kun. Until such a time that the original timeline can be restored, Ben-kun must be Den-O in Ryotaro-kun’s place.”

            Momotaros groaned angrily, sounding as though he were about to fight Owner. But after another minute or two of Owner impassively watching him, he calmed down and inclined his head toward Ben.

            “Fine. This way.”

            Ben started to follow Momotaros out, but Owner called out, “Ben-kun,” making him stop and turn.

            “Uh, yes?” he asked.

            “As you may have noticed, our translator has a problem with English.” At this, Ben looked down at the Ultimatrix; now that he thought of it, he wondered why it hadn’t overridden the malfunctioning translator the others must have been using. “If you get into any trouble, hold out your pass and call out, ‘Henshin.’”

            “Henshin,” Ben repeated, as Momotaros looked up at the ceiling in annoyance. “Got it.”

            “Hey, hey!” Momotaros called, taking Ben by the shoulders and turning him around to push him through the door. “Let’s go, let’s go, let’s go!”

            Momotaros pushed Ben through the other cars, where passengers took no notice of a teenage human being pushed along by an annoyed Imagin. For all Ben knew, this could have been a normal occurrence on DenLiner. When they finally reached the front of the train, Ben saw a sport motorcycle running in place in front of the window. Every so often, the handlebar of the bike would turn, and so too would the tracks being formed in front of DenLiner.

            “Whoa,” he breathed. “This is DenBird? It’s running the train?”

            “What did you think could power something like this?” Momotaros asked. “Don’t think Owner’s just going to get on a bicycle?”

            Ben was about to argue with him, but he held out his hand. Realizing that Momotaros needed the ticket and pass, he handed them over. Expertly, Momotaros inserted the ticket into the pass and flipped the top to the opposite side before inserting the whole thing into a slot in the bike’s dashboard. The moment he did, a new rail formed in front of DenLiner, splitting off from the main line.

            “Nice,” Ben said, taking the handlebars.

            “Hey, what do you think you’re doing?” Momotaros asked, putting his hands on the bars ahead of his.

            “Owner said I’d have to be Den-O for now,” Ben pointed out. “Isn’t this Den-O’s job?”

            “Feh, you’re not Den-O _yet_ ,” Momotaros argued, swinging a leg over the bike. “And after all you broke, you’re lucky I’m letting you join in the climax in the first place.”

            Ben raised his eyebrow, wondering if the translator had glitched again. Momotaros’s use of “climax” didn’t seem to fit properly. But even if he did say anything, Momotaros wasn’t listening. He was already steering the bike and train over to the new track as it lifted off the ground and rose into the air. A small vortex had formed in the sky.

            “You might want to hold onto something,” Momotaros said as Ben began to brace himself against the wall. “The climax starts now!”


	2. Always At A Climax

**Summary for the Chapter:**

> Ben's battle against the Cinderella Imagin could have gone better, but he and Momotaros are ready to redeem themselves against another Imagin. And Julie can't help but feel disappointed that the boy she cares about missed her tennis match.

            The train felt uncomfortably cramped. Unlike DenLiner, it hadn’t been intended to carry more than just a very few people, and for a long time, it had only had two riders. While there were only five passengers now, it was much more crowded than it should have been.

            One of them checked his pocketwatch, casually ignoring the uncomfortable glances the others were all giving it. In a cheerful British accent, he said, “There we go—right on schedule. Everything should be set right soon enough, or close enough to right, at least.”

            “What a relief,” sighed another.

            “But how are we going to get everything the way it was?” a third asked.

            “That’s something you’ll have to figure out on your own, I’m afraid,” the first replied. “And don’t be surprised if your pasts don’t line up. There will have to be a lot of twisting of time to fit around you.”

            “Thank you, Hakase,” the fourth replied, bowing slightly.

            “There is one more thing, however,” he replied, turning to the fifth passenger with a serious and regretful expression. “I have no right to ask this of you, after all you’ve given up. But I need you to do one thing if we are going to stop this.”

            He handed over a single item, and immediately everyone else was ready to protest, but the fifth nodded and took it with a combination of ease and heaviness that came from long experience.

            “I understand. I’ll do it.”

 

Derailed  
Chapter Two: “Always At A Climax”

                                          

            The time portal led away from Earth itself, and tracks formed in the starry blackness of space. Momotaros brought DenLiner alongside a ship and whistled.

            “Not bad,” he said. “Never ended up in outer space before.”

            “I think this is the ship bringing the Omnitrix to Earth,” Ben realized. “It was supposed to go to my grandpa, but I got to it first.”

            “And now we gotta make sure the Imagin doesn’t get to it before him,” Momotaros said. He got off of DenBird and went over to the door, but Ben stared at him in shock. “You coming?”

            “It’s a vacuum!” he protested. “We open the door, the whole train’s going to depressurize.”

            “Heh,” Momotaros snickered, opening the door.

            Ben braced himself for the vacuum and started to reach for the Ultimatrix, but the door opened to the interior of the ship. Aside from a slight rainbow shimmer along the edges, it looked as though they’d just opened a door between train cars. Shocked, Ben walked over, following Momotaros inside.

            “You’re just as bad as Ryotaro when he first saw all this,” Momotaros noticed. “Though you didn’t faint—you got _that_ at least.”

            Ben frowned as he looked at Momotaros. “I’m not here to replace your friend. I want everything back to normal just as much as you do.” Momotaros watched him for a moment, apparently analyzing him. Tired of being measured so much that day, Ben started to walk past him. “Come on. The Omnitrix is probably in the cargo bay, and it’s too small a ship to be too hard to find.” And as Ben made his way down the corridor, Momotaros tilted his head slightly before following him.

            It was surprisingly difficult to find the cargo bay, and they made several wrong turns, but Ben didn’t want to try to access the ship’s computer out of fear of alerting the crew. The last thing he wanted to do was cause more damage to the timeline.

            Momotaros sniffed the air. “That Imagin must be as lost as we are. Her stink’s all over the place. Think she might be ahead of us.”

            Ben turned a corner, finally finding the cargo bay. “Not for long.”

            They entered the cargo bay, where the Omnitrix was sitting in a small escape pod, ready to be ejected in case of emergency. As Ben made his way closer, Momotaros continued to sniff the air, looking all over.

            “The stink’s all over here, but no Imagin,” he noticed, even checking the ceiling. “So where’s…”

            The realization hit him, and he looked over at Ben, who had his hand over the Omnitrix's case to release the genetic lock. There was sand falling off of his body.

            “Ben!” he shouted. “Stop!”

            Ben stopped immediately and turned to Momotaros in confusion. “What?”

            Suddenly, sand exploded off of his body with such force that he was thrown to the floor. The Cinderella Imagin formed itself from the sand and looked at him.

            "Our contract's complete," she said, her voice so unnervingly like Julie's.

            "No," Ben argued. "This isn't what I wanted!"

            "It's what you wished for," she insisted. "As payment, I must take your most precious memory."

            "Like hell you will!" Momotaros argued, summoning a sword. He shoved Ben out of the way and charged her, making a powerful downward swing. The Imagin just managed to dodge it, turning toward him.

            “That’s why I smelled you all over the place,” Momotaros realized. “You were still inside Ben the entire time, waiting for him to come to this time. Hey! Ben! Can you get up?”

            “Yeah,” he groaned, getting to his feet. His arm was sore from his landing, but he reached for the Ultimatrix. “She might have gotten me twice, but I’m not going to let it happen a third time. It’s hero time!”

            He rotated the dial and slammed it down, but to his shock, nothing happened. No light, no sound—not even a sign that it had broken. He hit the dial over and over in a desperate attempt to make it work, but it was useless. It was like it had never worked at all.

            And Ben gasped in shock when he realized this was exactly the case. The Ultimatrix’s translator hadn’t worked on DenLiner, and now it wasn’t letting him transform because it had never been completed. Without him having the Omnitrix, Albedo never would have had a reason to put the Ultimatrix together.

            The Imagin had extended one of her vines to create a sword and was locked in combat against Momotaros. She shoved him against the case and tried to bring her sword down on him, but he held up his own to block her. When he looked over to see Ben standing in total shock, he called out, “Hey! What’s wrong with you?”

            Ben’s shock turned into fear as he looked over at Momotaros. “I can’t use the Ultimatrix.”

            “What do you need that for?” Momotaros demanded, pushing the Imagin off long enough to toss Ben the pass. “Do what Owner told you! Henshin!”

            That was right. In the chaos, Ben had forgotten all about Owner’s instructions. As he caught the pass, a belt formed around his body, just hanging off. He clipped it together, noticing some kind of scanner in the middle. Getting an idea of what he needed to do, he held out the pass and scanned it over the belt.

            “Henshin!”

            White light flashed from the center of the belt, and constructs like train rails flew through the air before converging on his body. When they did, Ben’s body was covered in a black suit with silver and black, light armor. A white-and-black helmet with full mask protected his face, the same train-rail motif running down his helmet and armor. And in addition to the pass on the side of his belt, he now had a three-part weapon, still in pieces.

            “Whoa,” he breathed. “This is Den-O?”

            Momotaros, who was once again grappling with the Cinderella Imagin, was less than impressed. “That’s only Plat Form! It’s not going to do anything!”

            But completely ignoring him, Ben was already running into battle, grabbing the Imagin from behind. It was enough of a distraction for Momotaros to throw the Imagin off of him with a powerful downward slash.

            With Ben holding the Imagin, Momotaros waved his sword in anticipation. “Here we go, hissatsu! My hissatsu attack, Momotaros version!”

            He swung the sword again, but the Imagin whirled around, as if dancing, creating a powerful energy field that threw the both of them back.

            “What?! How'd some pumpkin girl break my hissatsu?" Momotaros cried in disbelief.

            Ben groaned as he struggled to get back to his feet. “She’s going to break more if she gets to that case.”

            Cinderella came to a stop before the case and held out her sword. But before she could cut through it, a jolt rocked the whole ship, forcing her away.

            “What was that?” Momotaros asked.

            “The ship’s under attack,” Ben answered. “Never thought I’d be grateful for Vilgax showing up.”

            Momotaros moved closer to Ben, helping him stand. “Not gonna be enough for now. Lend me your body.”

            Ben looked at him, wondering if this was another glitch in the translator. That could _not_ have been what he just heard. “What?”

            “I’m an Imagin, remember?” Momotaros pointed out. “I can possess you. Sword Form’s got a lot more power than Plat Form. Just press the red button!”

            Cinderella had recovered and was making her move. Ben had no time to argue. He pressed the red button and hoped for the best. Music chimed from the belt, and Momotaros’s form became luminous and transparent as he _jumped_ into Ben’s body, forcing him to stagger a little bit from the sudden shock. But the two minds settled soon enough, and Momotaros-Ben scanned the pass over the belt once more, forcing it to intone, [Sword Form.]

            Faint, red light pulsed from the belt, and rails made of colored light surrounded Den-O once more. Pieces of red armor flew around him before settling on his body—stronger and more protective than the basic Plat Form armor. A new red visor formed on the helmet, splitting apart to form separate eyes. Thrilled to join the fight, Den-O Sword Form struck a pose and declared, “Ore sanjou!”

            There was a pause within their shared mind before Ben asked, _“What?”_

            Ignoring him, Momotaros answered, “Now, Ben, I’m gonna show you what it means to start and end at a climax!”

            He took the three pieces of the weapon, throwing one in the air before connecting it to the other two to create a sword. With a shout of “Let’s go, let’s go, let’s go!” he charged at the Imagin, swinging wildly. The Imagin pulled away as the sword hit the floor, but a sideways slash hit her. Inwardly, Ben cringed at her cry of pain. It had actually done some damage, from the combined power of Momotaros, Ben, and Den-O. The Imagin hit the floor, and Momotaros held up the pass.

            “I’d really like to rampage more, but it looks like I’ve got to hurry this up. My hissatsu attack, part one!”

            He scanned the pass over the belt, which noted, [Full Charge.] A line of red energy went around the sword, charging it up. He tossed the pass aside and ran at the Imagin with the glowing sword. The Imagin looked up, her eyes looking almost sad...

            _"Stop,"_ Ben insisted.

            "What?!" Momotaros cried, stopping just short of her face. _What are you doing, Ben? We gotta get rid of her!_

Ben tried to move through the pain in his heart, and he said, _"The airlock. That way, we get rid of her and get the Omnitrix safely to Earth."_

            "Well, if you're sure," Momotaros agreed, turning his attack on one of the doors.

            The vacuum hit immediately, and Momotaros shrieked before grabbing tight to the handle as the Omnitrix was sucked out toward Earth's atmosphere. Cinderella tried to hold on too, but she couldn't keep hold and went flying out along with it. Momotaros turned to watch, and Ben wished he hadn't—as she fell toward the planet, her body began to burn.

            "Got to get inside," Momotaros insisted.

            He started trying to pull himself in, but DenLiner pulled up right alongside the ship, and a door opened.

            _"There!"_ Ben insisted. _"Jump!"_

            Momotaros let go and screamed all the way as they reached the door and tumbled in. The door hissed shut behind them, and Momotaros separated from Ben's body, landing in a heap beside him.

            Ben looked at his wrist. All that remained of the Ultimatrix was a trace of sand around his arm.

            "Welcome back!" Naomi chirped, standing over them and reaching down to help them up. "Owner asked me to open the door for you."

            "Thanks," Ben said, taking her hand. "You came just in time."

            "Oh, my back," Momotaros moaned, stretching. "But it wasn't too bad being in your body. Just about as weedy as Ryotaro, but you’ve got more stamina, at least.”

            "Thanks," Ben deadpanned.

            They entered the dining car, where Momotaros took a seat by the coffee bar and Owner was eating a plate of fried rice.

            "I take it your mission to destroy the Imagin was a success?" he asked.

            "Pretty much," Ben said. "We threw her out into space."

            "Then how can you be sure that you destroyed her?" he challenged.

            Ben looked down. Another mistake. "I can't."

            The flag tipped over. Owner raised his hands in alarm, then pushed his plate away to look at Ben. “Ben-kun, you may have made a serious error in judgment, but you will have to deal with the consequences for that later.” Ben nodded reluctantly, and Owner’s stern expression suddenly broke into a smile. “For now, would you like to see the new time you’ve created?”

 

~~~

 

            Daylight broke over a new timeline. The sun started to peek into the window, just seconds before the alarm clock went off. Automatically, her hand reached over to switch it off.

            Julie sat up and rubbed the sleep out of her eyes before looking outside at the fading stars.

            “I can’t believe he missed it,” she murmured.

            Finally, she got out of bed and started pulling up her sheets. She didn’t have time to waste worrying about this, after all, and she’d confront him on it when the time came.

 

~~~

 

            The door from DenLiner had opened to a rooftop in the city closest to Bellwood. Ben leaned against the protective railing, watching the sun rise over a time without him. Beside him, Momotaros’s head and torso were sticking out of the floor while his legs dangled overhead, all composed of sand.

            “Weird thinking that nobody knows me now,” Ben said, rubbing his left wrist. Naomi had given him a watch so he could time DenLiner’s scheduled stops, but even with that, his arm felt bare.

            “Eh, we’ll get you settled back in eventually,” Momotaros replied.

            Ben couldn’t help but smile. “So, guess I’m not so bad after all?”

            “Well, you’re not Ryotaro,” he admitted, “but as a sub, you’re not half bad.”

            Ben grinned. “Guess I can accept that. Just got a question for you.”

            “Shoot.”

            “Why are you like that?” He gestured to Momotaros’s sandy appearance. “Why don’t you have your normal body?”

            Momotaros shrugged, releasing some sand. “DenLiner’s the only place I can show up in my full body. Was the same for Ryotaro, since he didn’t have a wish I could fulfill.”

            Ben stared at Momotaros in shock. “But you _were_ in your normal body before—on the ship.”

            Momotaros gave Ben a look that clearly suggested he thought he was crazy. “No, I wasn’t.”

            “Yes, you were,” Ben insisted. “That’s how we fought the Imagin, until you possessed me.”

            Momotaros stared at Ben for a long moment before shouting in frustration, “I can’t believe it! We changed the past somehow!”

            “Great,” Ben groaned, sinking to the floor. “And since I’m the singular point, I’m the only one who remembers it.”

            Momotaros had been pacing around in aggravation, and the sight of his legs walking around in midair would have been funny if Ben weren’t so worried about what damage he’d done to the timeline. But seeing that worry, Momotaros stopped and said, “Hey. If you’re right about me fulfilling Ryotaro’s contract, that means I’ve got a new one with you. So we’re both going to work together to put it right. Got it?”

            Ben managed a wry grin. “Wouldn’t have pegged you for the supportive type.”

            “Hey!” Momotaros argued. “Don’t start thinking I’m soft. I mean it when I say from start to finish, I’m always at a climax!”

            Ben laughed and shook his head. “Do you even know what that means?”

            “What’s that supposed to mean?” Momotaros demanded, but Ben was getting to his feet. “Hey, where are you going?”

            He looked back at him with a grin. “I haven’t been able to go anywhere without reporters chasing me down for _months._ I might as well make the most of it.”

            As Ben dashed inside, Momotaros noticed, “Heh. Resilient one, this one.”

            It took a second for him to realize he was getting left behind.

            “Hey! Wait up!”

 

~~~

 

            “Hey, Julie, great match last night!” called out one of the boys as they passed her on the way to school.

            She smiled. “Thanks.”

            A girl near the boy snickered and elbowed him before dragging him off. “Come on, lover boy. You know she’s taken.”

            “Aren’t you coming?” asked one of the girls on her tennis team.

            “I’ll catch up,” she promised. “I’m waiting for someone.”

            The girl shook her head. “He’s in the doghouse tonight!”

            Julie sighed as the kids all passed her by. She was used to this and didn’t bother correcting them. Let them think whatever they wanted.

            A train whistle sounded nearby—a musical sound that nobody else drew the connection to. Julie ran toward the sound, following it to an empty street. A two-car train was waiting there, and a young man stepped off.

            Julie crossed her arms. “You missed my game.”

            “Couldn’t be helped,” he answered, walking past her.

            She frowned. “That’s what you say all the time. You promised.” He came to a stop. Seeing her chance, she insisted, “What happened, Yuto?”

            His body jerked suddenly as a green flash entered him. His hair suddenly grew out, with a dual-toned streak of green running through it. The possessed Yuto suddenly turned around, his eyes bright green and full of regret as he bowed deeply.

            “Please forgive Yuto, Julie-san!” he apologized. “He really wanted to come to your match, honestly! But something important came up!”

            _“Idiot!”_ came a mental cry loud enough for even Julie to hear. There was a green flash again, and a black monk-like Imagin in green and black robes and a gold, bird-like mask was ejected from him.

            “Deneb!” Yuto shouted. “What have I said about putting words in my mouth?”

            He started to lunge for the Imagin, but Julie put herself between them, and he stopped short.

            “That’s enough,” she insisted. With a glance back to the Imagin, who was getting to his feet, she said, “Deneb, you don’t have to apologize for him. I’d rather hear it from him anyway.” She turned her attention back to Yuto. “It was an Imagin, wasn’t it?”

            Yuto sighed in frustration. “Yeah. The same one we’ve been tracking down. It was active last night, but it disappeared.”

            A wave of sadness and worry washed over Julie as she looked at him, and he wouldn’t meet her eyes. “Are you planning on fighting it?”

            “What do you want me to do?” he snapped, but she gave him a flat look until his temper cooled, and he responded, “It’s the only way to keep time safe.”

            “Be careful,” she insisted.

            He gave her a smile that she knew right away was fake. “Don’t worry about me. You know I’m pretty strong.”

            The unaddressed tension was thick enough to cut with a knife, but fortunately, Deneb always knew just how to ruin a moment. With a sudden cry of, “Oh, Yuto!” he hurriedly handed over a small box wrapped in a cloth napkin. “You almost forgot your bento!”

            Yuto took it, automatically replying, “You better not have put shiitake in here.”

            Julie shook her head, a helpless smile on her face as he started to walk off toward school. That was Yuto—always upset about _something_. As she started to follow, Deneb stopped her and handed her a similar box. “One for you too, Julie-san.”

            “Thanks, Deneb,” she replied. Quietly, she asked, “Take care of Yuto, please?”

            He nodded emphatically. “Of course, Julie-san. We both will. Now, hurry to class before you’re late!”

            Julie smiled and left, waving goodbye. She had no doubts about Deneb. In the time she’d known the Imagin, she’d seen how reliable he was. Sure, he was clumsy, self-effacing, a bit of a mother hen, and he didn’t always get social situations, but he cared deeply about Yuto and Julie, and he did everything possible to help them—much to Yuto’s annoyance.

            Yuto Sakurai, however, was another matter entirely. He’d come to America from Japan a year ago and transferred to her school, supposedly to improve his English, but Julie had soon found out about the time train ZeroLiner and Deneb, along with their mission to stop the Imagin from destroying time. Unlike Deneb, Yuto was hard to get close to. He was stubborn, immature, rude, and always pushing people away.

            And yet he was her best friend.

            Funny how things worked out.

 

~~~

 

            Without a physical form, Momotaros was free to go between DenLiner and Earth as much as he wanted, and the contract with Ben created a mental link between them to keep in contact—similar to telepathy. As he walked though the city—just another anonymous face in a sea of people—Ben couldn’t help but think, _It’s kind of weird having you in my thoughts like that._

_“You resist a lot more than Ryotaro ever did,”_ Momotaros admitted. _“Your mind’s set up differently, like you’re used to this.”_

_Kind of,_ Ben answered. _Only, it was always a bad thing when I could hear my aliens’ minds._

            He was so focused on the mental conversation that he didn’t watch where he was going and ended up bumping into a girl, knocking a case right out of her hands.

            “Sorry!” he apologized immediately, bending down to pick up the case. He realized suddenly that it was a tennis racket case, and he looked up at the girl. To his immense relief, she was an unfamiliar girl with blond hair.

            “It’s okay,” she insisted, taking the case from him. With her closer, Ben could smell a very strong, flowery scent on her, and he had to resist the urge to sneeze. “I was a little distracted myself.”

            As he stood up, he gestured at the case and asked, “Bad game?”

            The girl sighed and nodded. “Third time straight this girl’s beaten me. Nobody even knew her name before the end of last year.”

            Ben gave a sympathetic smile. “That’s rough.”

            “Tell me about it,” she replied before looking at her watch. “I’m going to be late. Thanks.”

            “No problem,” Ben answered, but the girl ran off.

            _“Heh,”_ Momotaros said. _“First day, and already you’re trying to impress the girls.”_

            “Not this one,” Ben replied, making a face. “I don’t know what kind of perfume she was wearing, but it was too strong.”

            _“Eh?”_ Momotaros asked.

            “Yeah, she smelled like roses,” Ben answered. “A whole field of them. I think I’ve still got the scent on me.”

            He lifted the hand that had picked up the girl’s case to sniff it, then stopped in shock when he saw sand.

            _“An Imagin?”_ Momotaros asked in shock. _“How come I didn't smell it?”_

            “All of that perfume must have covered it up,” Ben realized. He looked back to find her, but she was already gone. “Lost her.”

            _“Move over!”_ Momotaros ordered, and with a quick jolt, he jumped into Ben’s body. His hair was now spiked toward the back, with a streak of red running through it, and his eyes were startlingly red. Also red was his jacket—just as red as Albedo's had been, and Ben would have been more weirded out if it weren't for the fact that he was just possessed by an Imagin _again._ Getting into a low stance and pointing at himself, he declared, “Ore sanjou!” before spreading out his arms.

            Ben didn’t miss the fact that people were staring. _“And now everyone thinks I’m crazy. Thanks.”_

“Feh,” Momotaros said, straightening. “What good is a climax if you’re not going to enjoy it?”

            _“…Remind me to buy you a dictionary.”_

            Ignoring Ben’s complaints, Momotaros shouted, “Let’s go!” and took off after the girl. But once he’d reached her, she’d fallen to the ground, an Imagin rising from the sand before her. Where the Cinderella Imagin had been beautiful, this one was decidedly not. The right side of his torso seemed to be made of rose petals, his right arm a mass of thorny vines emerging from the petals and ending with sharp claws. The thorny vines extended to the right leg too, but most of it—along with the whole left side of the body, was a wild, furry creature in tan. The Imagin’s face looked a bit like a wild dog, with exposed teeth and one floppy ear on the right side. On the left side of his head was a large rose.

            _“That’s a face only a mother could love,”_ Ben decided. _“We’d better…”_

            “Already on it,” Momotaros answered, whipping on the belt and holding up the pass. “Henshin!”

            As before, the rails of light converged on him to create the armor, but this time, the track of light circled him and the Sword Form armor attached itself. Momotaros took the pieces of Den-O’s weapon, the DenGasher, and put them together as a sword.

            “Hey, ugly,” Momotaros called, resting it against his shoulder. “We already lost one of you guys in the past. I’m eager to make up that loss.”

            “Just try!” the Rosebeast Imagin growled.

            “Let’s go, let’s go, let’s go!” Momotaros shouted, swinging the DenGasher.

            The Imagin leapt back from the initial attack, and when Momotaros brought the sword back up in a reverse slash, it passed right through the Rosebeast in a flurry of petals.

            “What?” he asked in shock before a claw rammed into him. He fell to the ground, landing not far from the contract holder, who was screaming in terror. “Hey, flower girl—get out of here!”

            She didn’t need a second warning, leaving everything and running for her life. The Rosebeast didn’t seem too worried, clawing at Momotaros again while he blocked with the DenGasher. He tried to counterattack, but the sword passed through him again. Furious, Momotaros kept slashing, but he just couldn’t seem to score a hit.

            “What is wrong with this thing?” he shouted.

            “You can’t touch me,” the Rosebeast taunted. “Now, to fulfill my contract!”

            More petals flew through the air as he darted off. Growling in frustration, Momotaros got to his feet as DenLiner arrived. The engine opened, and DenBird sped out. With a running leap, Momotaros got on the motorcycle and took chase.

**Notes for the Chapter:**

> The style of this chapter is a little different from what I usually do because I wanted to keep true to Momotaros’s motto of “From start to finish, I’m always at a climax!” And given the decided anti-climax of that first battle, he needed to finish by fighting again. As a translation note for those migrating over from Ben 10, “ore sanjou” is roughly equivalent to “I have arrived,” but it definitely loses the cocky connotation in English, so it’s generally kept in Japanese. Poor Ben is going to run into quite a few problems with the language.
> 
> Another note: Don’t ask about the apparent Deneb/Julie I ended up slipping in here. Just don’t. So far, I’ve got only one intentional ship in this. Anything else is just a bonus. So if you prefer Ben/Momotaros, go for it. Same for Yuto/Julie or Deneb/Julie. I’m determined to introduce as many alternative crackships as humanly possible. It’s meant to be fun first and foremost.
> 
> Each Imagin is based off of some kind of folklore or mythology (such as Momotaros being inspired by the tale of Momotaro, the Peach Boy). Ben’s is Cinderella, with a touch of heavy symbolism about his relationship with Julie. The Rosebeast is based on the fairytale Beauty and the Beast.

**Author's Note:**

>  _Ben 10: Ultimate Alien_ is the property of Cartoon Network, and _Kamen Rider Den-O_ is the property of Toei. The title comes from a line spoken by the Tenth Doctor in the _Doctor Who_ episode “The Shakespeare Code”:
> 
> Martha: It's like in the films—if you step on a butterfly, you change the future of the human race.  
> Doctor: Oh, well, then don't step on any butterflies. What have butterflies ever done to you?
> 
> To mesh the timelines of both series, I’ve set the original _Ben 10_ in 2007. While this fic was started after “The Transmogrification of Eunice” and “Eye of the Beholder,” it’s not so much meant to resolve the Ben/Julie breakup as it is to cope with Ben’s myriad of issues with his identity being revealed throughout _Ultimate Alien_. But I’m going to try to steer clear of too much angst in this; it’s meant to be a fun crossover.


End file.
